Alloy



5o alloy aside from its great strength, is its is controlled primaril by the pouring tem- 1 was a... 29,1921. 1,622,576

UNITED. sra'res PATENT OFFICE.

JOHN 1v. EARLY, or PITTSBURGH, PENNSYLVANIA.

ALLOY.

Ho Drawing. Application filed July 21, 1926. Serial No. 124,105.

This invention relates to an alloy of iron, ordinarily used for this purpose several the main constituents of which are iron, times. silicon, sulfur, hosphorus, manganese, car- The depth of the chill on castings formed 1 bon, and molybdbnum, with or without small from this alloy is readily controlled by varyquantities of either nickel or chromium or ing the sulfur content and by varying the both. heat'at which the metal is poured.

-This alloy is characterized by having The molybdenum may be added to the great strength and a very hard chill surface, mix as molybdenum scrap, as ferro-molyb also that the chill depth may be readily condenum, or as calcium molybdate, and is 10 trolled b the operator, either in a sand or preferably added after the other metals of I chill mo (1. the mix have .melted and just long enough This alloy may be used for making all before tapping the heat to permit of it becommercial castings requiring hardness and coming thoroughly diffused throughout the tensile strength, such as rolling mill guides, bath.

15 rolling mill rolls, crusher rolls, and the like. The nickel and chromium serve to increase Heretofore, in casting iron alloys the chill the tensile I strength and toughness of the depth has been uncontrollable, except by the alloy and may be omitted for some purposes, use of chill pieces or chill molds, and even however, when makin rolling mill rolls then has been more or less of an uncertain chromium will prefera ly be used and in 20 matter, while the present alloy permits of some cases nickel will also be used although positive control of the chill depth at all the nickel is not essential. times. In producingthis novel alloy, the follow- Generically, the invention consists in an ing method is carried out i alloy containing the elements and the per A cupola or other smelting furnace is first 25 centages thereof, follow1ngcharged with suitable scrap, pigs, or ores, of so Per cent. the proper analysis to produce the proper Silicon .75to1.50 proportion of silicon, sulfur, hosphorus, Sulfur ,05 to .35 manganese, and carbon, and if chromium Phosphorus .25 to .7 5 or nickel are to be included in the alloy, suit- Manganese .20to .70 able pigs or scrap containing these ingre- Carbon 2.00to3.75 dients are also added. After the mix is Nickel .05 to .25 made up it is heated to from 2500 to 2700 Chromium .15 to .25 degrees Fahrenheit to melt the metals. That Molybdenum .10 to .30 is, the mix is raised to a heat materially 35 Iron sufiicient to make 100%. above the melting temperature in order to obtain a good pouring temperature. The

Castings made from this alloy show remolybdenum is preferably added after the =markable results in tensile-strength and in mix is melted down and just long enough wearing quality, and in v the resistance to before tapping the heat to permit it to be- 40 the action of heat. come thoroughly diffused throughout the The molybdenum increases the tensile bath, although the molybdenum may be strength of the alloy 1 and the high sulfur added at any time during the melting operacontent causes a greater amount of the cartion or as scrap when making up the mix if bon to become combined than would otherdesired. a 45 wise be the case. Mol bdenum also raises After the mix is melted it is tapped and 0 the ratio of the elastic, imit to the ultimate then poured into the molds at a temperature strength of the metal'and benefits the dueof from 2300. degrees to 2500 degrees Fahtility. renheit.

The most notable characteristic of this The depth of chill on the finished casting abihty to chill in either a sand or chill mold, perature. That is, t e holler the pouring and the ease with which the operator can temperature the deeperwill be the chill; also I control the depth of chill. the depth of chill can be controlled some- When rolls are formed from this alloy they what by the sulfur content of the mix, that 66 will outwear ordinary rolls made from alloys is, the greater the sulfur content the greater ranges, 10

I the chill. However, the sulfur content is known and when it is slightly higher or lower than necessary to produce the correct depth of chill, the pouring temperature may be increased or lowered accordingly to give the correct depth of chill.

While I have described certain specific combinations of elements within certain it will be understood that I do not wish to be limited thereto beyond the express limits of the appended claim which is meant to cover various modifications and equivalents as may be readily practiced by those skilled in the art to which this inveni tion belongs, i

I claim- A ferrous metal alloy'primarily suited for the making of castings having a hard chilled surface such as rolling mill rolls, and capable of forming a controllable chill in a sand mold without the use of chills, said alloy containing the following elements in substantially the following proportions- Per cent. Silicon 75 to 1. 50 Sulfur 05 to .35 Phosphorus 25 t 7 Manganese to 7 0 Carbon 2. 00 to 3.75 Nickel ..05 to .25 Chromium 15 to Molybdenum 10 to Iron approximately suflicient to complete In testimony whereof, I have hereunto signed my name.

JOHN N. EARLY. 

